Chemistry! Instead of transporting compressed gas in the car to inflate the airbag, we take advantage of a very fast reaction that produces the needed gas. Many car airbag inflators contain small amounts of a toxic molecule called sodium azide, or NaN3 (one sodium atom and three nitrogen atoms combined).
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How is chemistry used in airbags?
The answer would be found in a fascinating chemical called sodium azide, NaN3. When this substance is ignited by a spark it releases nitrogen gas which can instantly inflate an airbag.
What triggers an airbag to inflate?
The instant a crash begins, sensors start to measure impact severity. If the crash is severe enough, the sensors signal inflators to fill the bags with gas in a fraction of a second. Airbags don’t typically require maintenance unless they deploy in a crash.
How do airbags use stoichiometry?
The rapid chemical decomposition of solid sodi- um azide, NaN3, allows the air bag to inflate fast at any time. The decompo- sition reaction is initiated in a car by a small ignition induced by a collision sensing mechanism. The nitrogen gas produced during the reaction inflates the air bag.
Why are airbags filled with nitrogen?
Nitrogen is clearly safer and more effective in air bags than compressed air. Analogously, nitrogen inertion helps improve fuel economy of motor vehicles, does not oxidize rubber, and is a safe alternative to compressed air.
Why is potassium nitrate also in airbags?
The first automotive airbags developed in the 1970s employed a solid propellant. These airbag inflation systems reacted sodium azide (NaN3) with potassium nitrate (KNO3) in order to produce nitrogen gas. Hot blasts of nitrogen gas inflated the airbag.
Why is a decomposition reaction chosen to inflate airbags?
When sodium azide decomposes it generates solid sodium and nitrogen gas, making it a great way to inflate something as the small volume of solid turns into a large volume of gas. The decomposition of sodium azide (Equation 1), results in sodium metal which is highly reactive and potentially explosive.
Why do airbags inflate and deflate quickly?
It also spreads the impact over a larger area of the body. That way, no single area (forehead, chin, neck) bears the brunt of it. That’s why airbags inflate and then quickly deflate—to gradually bring the driver’s momentum from 60 mph to zero.
How airbag works step by step?
At what speed do airbags inflate?
Air Bag Deployment An igniter in the inflator starts a chemical reaction that produces a harmless gas, which inflates the air bag within the blink of an eye – or less than 1/20th of a second.
Which gas law do airbags use?
Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, , with excess heat, a large amount of Nitrogen gas () is created.
Is airbag gas toxic?
Airbags cause no chemical injuries. The sodium azide they contain is used up when they deploy, and the gas produced, nitrogen, is not harmful (The air we breathe is 78% nitrogen). The dust released from air bags may have some sodium hydroxide in it.
How much gas fills a typical airbag?
A typical driver-side airbag contains approximately 50–80 g of NaN3, with the larger passenger-side airbag containing about 250 g. Within about 40 milliseconds of impact, all these components react in three separate reactions that produce nitrogen gas.
Is airbag dust toxic?
Breathing problems from airbag dust in the lungs. Headaches, skin or eye irritation, dizziness, weakness, blurred vision, low blood pressure, slow heart rate, and effects on the kidneys from exposure to sodium azide, according to the Centers for Disease Control and Prevention (CDC)
What is the maximum pressure in an airbag?
Most high pressure air bag systems have a maximum working pressure of 8 bar/116 psi or 10 bar/145 psi.
What is the explosive in airbags?
Most airbags are inflated when the inflator unit ignites a pellet of a compound called sodium azide (NAN3), kickstarting a swift chemical reaction that fills up the airbag with nitrogen gas (N2), sending it bursting out to cushion a car’s occupants.
Are airbags endothermic or exothermic?
The performance of airbag and its deployment are based on a fast exothermic-chemical reaction. The hot gas resulting from the chemical reaction which results in airbag deployment can cause thermal damage and skin burning for the car passenger.
How many PSI does an airbag deploy?
But even as it is filling with nitrogen gas, an airbag is already venting so that when the human body makes contact, it’s not running into the equivalent of a fully inflated Pirelli P7 radial. In fact, the maximum pressure in an airbag is less than 5 psi—even in the middle of a crash event.
Do airbags go off if your seatbelt is not on?
According to experts, many are not aware that in some cars the airbags — the ones in front of the driver as well as the co-passenger — would open only if the seatbelt is worn. “Airbags will not activate if seatbelts are not fastened,” said Graeme McRaith, Service Operations Manager, Zawawi Trading Co.
Can I sue Toyota for airbags not deploying?
Yes, you can sue if your airbags did not deploy during an accident.
How do airbags relate to Boyle’s law?
Boyle’s Law- When the airbag expands, the pressure decreases as the volume increases at a constant temperature.
What gas law best explains the blowing up a balloon?
Mathematically, Boyle’s law can be written as pV=k, where p is the pressure of the gas, V is the volume of the gas, and k is a constant. An example of Boyle’s law in action can be seen in a balloon. Air is blown into the balloon; the pressure of that air pushes on the rubber, making the balloon expand.
What is gas law chemistry?
The law states that at a constant volume, the pressure of the gas is directly proportional to the temperature for a given gas.
Do airbags hurt?
Many drivers have endured broken bones in their chest, and damage to soft tissue. Burn and Laceration Injuries – The speed at which airbag deploys can cause abrasions or burns. The face and arms are particularly vulnerable to getting burned.
Why do airbags have powder?
The residue is primarily corn starch or talcum powder, which is used to lubricate the bag as it deploys, and by-products of the chemical reaction that produces the nitrogen gas to inflate the air bag. This residue may contain a small amount of a potential skin irritant, sodium hydroxide.